delorean6584

hi all, as you know i broke 2 piston skirts on my l28et wich was running really good before (due to stuck rings) the engine was pulling real hard en perfectly....so i swap a l28 bottom end f54 with flattops, hooked all the stuff right back, only changed the map for the timing in the ms2...i expected as it would pull as hard(atleast off boost) but it is so sluggish ?? seems that the engine is slowing down when i accelerate, the boost is down to 5lbs, dont seem to ping fuel ratio is perfect...could it only be due to the timing map ? it is from 8degree at idle to 20 on max boos/rev ?? i just dont understand why its not working welll help !!!!

tony, i did replaced the pan gasket when i got the engine...no pieces were found.... the skirts are freshly broken it is obvious, the engine smoked oil and shaked like a v8 when they broke..... the no5 piston was surely damaged before (top section) i think i will run octane boost with each fill of gas to be sure... such a pita to swap all parts !! i also have only one good engine remaining !!!

yes i am pretty sure the skirts breaked because of the stucked rings, number 5 and 6 skirts were broke, these 2 pistons have stuck rings on them, the other pistons are like new, rings are not stuck....i guess when i bought this engine 2 years ago i should have replace the rings...i was hesitating if they were stuck or not, compression was good....live and learn !! as for my new engine, how much boost do you think it could handle to be reliable ? maybe i will run high octane gas just to be sure...i would like 10psi... is it possible without breaking anything ?

Hi all ! after finishing the megasquirt and acheiving good results with tuning it came the fun part ! broke a piston skirt !! i ran megasquirt, l28et completly stock engine good air/fuel ratio 15psi of boost and intercooled and BOV the thing is i bought this engine used and was sitting for 10 years or so, it was inside a barn and wasnt stuck, but maybe the rings were....so the number 5 piston have the skirt off but the rings intact (they are stuck to the piston though, so i removed another piston wich the cylinder and piston is good, the rings are stuck too.... so i imagine that the broken skirt is due to the stuck rings ??? if not ?? i never heard the engine pinging like popcorn at all, only the number 5 piston is broken all other are in very good shape ?? now what to do ??? i dont want to rebuilt it to break it again...there is now way i pushed 300hp on this motor, the boost is raised to 15psi but very well intercooled, engine coolant temps is always low... i ve put alot of money in this car and i am building my house right now, so money is a problem, but i have 2 sitting engines in my garage (l28e) they both work well, the blocks are the same but not the pistons or heads, my turbo head is good, so the question is, do you think the engine could be reliable if i take the l28e bottom end, put the turbo head on it with all the turbo goodies ? compression will be higher but i could remove some boost ? or i could get a l28et bottom end fairly cheap but i would need atleast new rings/polishing cylinders i really want a reliable engine, this is my daily driver but i want something a little more powerfull than the stock n/a.... comments are welcome ! EDIT : if it can help to find the reason it broke, the skirt is broken on the driver side... the Rh one is okay

thanks, yes i also have swastika wheels, i sandblasted them, polished the exterior and painted the center flat black, gives an amazing looks, i have 2 made, i have 2 remaining to polish !

UPDATE !!!!! i removed the dizzy again to try to test the wires, they were all good, so i tried to swap my old CPS in the dizzy and wow ! it works perfectly ??!!??, tried the new one...no rpm at all, so the new one is bad...and the old one is now good ! i cleaned the old one with brake cleaner because there was some dirt where the wheel goes so maybe it did the trick... i will return the bad new one to the store ! and i must say wow that car really have some power from 4000 to 5500 !! as soon as the tuning process will be more perfect i will dyno the car and post the results ! thanks all for the help ! heres a pic of the car before i put the hood on it... (notice the cool hybrid Z logo

just spent 200$ on a new crank position sensor for my dizzy and guess what?? problem still there ! i just don't understand, the wiring is brand new all over, dizzy wires are shielded from dizzy to ecu, i hooked the resistor and connected all thw wires per mobythevan sticky post...looks like the ecu have a problem ??

thanks for that input, yes i am sure the dizzy is the culprit...could be a fast way...and it is new....

just figured out that the drive shaft isnt the same, so back to square one !!! a cheap turbo dizzy or edis6

update !!, i didnt find what was the sound yet but i talked to one of my friend wich did had some problems on his car when raising the boost like i did, he had to install a external wastegate because the boost was higher than the spring in the wastegate actuator, thus opening the bypass valve, mine doesnt seem to loose boost though...atleast until 4500 (the dizzy cuts at 4500), so could it be possible that the bypass valve is beginning to open wich could create the whistling sound ?

sound like a good alternative, i didnt tough that a complete kit like this would be so cheap, new wiring to do tough... just finished the ms2 one.... but i won't buy a new dizzy, i will try to get one locally real cheap, if not available i will try to modify a n/a dizzy (i have 2), i don't have alot of time because i am buildint my new house, but if the n/a thing is to difficult to work with the edis6 will be the way to go ! thanks for the input !

sounds good to me !!

you are right matt, i took off the dizzy, hooked up a drill on it and watched/logged the megatune, wich cutted at 4500 like the car, but the drill wasnt loosing speed so the dizzy is bad ! does the captor inside is replaceable or i need a complete unit...this one if off ebay of last year, would prefer buy a new sensor than a 20+years old dizzy again!

do you have a 240sx tps? mine did the same thing when i first plugged it...but i connected it on the same connector as the stock l28 one...wich only give values for half and full wot, you must use the 3wires going out of it like 6inches long..but if it was working before i assume yours is properly connected...did you used the wiring diagram from msns extra sticky post? if its okay maybe you could use a small resistor between the wires to see if ms see a difference if yes your ts is wrong, i dont have my tps values handy but i could get these if you want... hope this helps

did you tried to calibrate it via the megatune tools ?

yayyy finally got able to attach the file !!!! here it is !!!!! datalog24mai.zip

you dont need to signup, just click the basic feature and its free, nothing to enter...i don't know how to attach it ?

ok i understand, i didnt hear that sound before because that engine wasnt mine, i bought the engine without the turbo and exhaust manifold, after installing all these components i used it in my spare car, wich didnt had any exhaust, the stock ecu wich wasnt working more than 50% of the time, so i didnt used it at all, now with all the new ecu, intercooler i hear it very loud...the gaskets for intake and exhaust are new, i dont see any leaks at all, the turbo is rebuilt, nothing is stuck...but it seems really like something coming from the wastegate, just like it opens too soon or the pressur push it just enough to allow some air to bypass and wistle...

Hi some news there....i tried to play with my dizzy to be sure it wasnt to far and same thing, cuts at 4500, so i logged the thing ! it is at idle speed to rev up to 4500, no driving there, some things are funny in that log, looks like something is happening, duty cycles are falling along with rpm... maybe you guys could tell what seems wrong.... here is the file http://www.filefactory.com/file/ag162b0/n/datalog24mai_xls

tried more on this one as options like rising edge in the spark settings, still cut at 4500....i'm lost ! help ! yan

my turbo is a rebuilt so the wastegate is not stuck, it is working perfectl, but i remeber seing a crack on the housing where the wastegate is...i asked for it on hybridz for that i had replies that it dont matter, the boost ir very good, but maybe could the crack making the sound ?? its not leaking anywhere though... i also tested the actuator with 40psi of ciompresed air, no leaks no sound, wastegate closed..

at 4500 the timing is at 35degree but from 3500 to 7000 it is 35 degree so if 35 was too much the engine would cut at 3500... but maybe it could be related to my basic timing offset wich is 43 degree....

is there any other kind of rev limiter in megatune ? or jumper in the MS box ?

the sound is like a howling, but only on hi loads never done that under 7psi of boost so i need to drive it hard to hear the sound, it sounds like coming from the left of the engine though....

i do not log with the LC-1, as for megatune the rpm cuts a 4500, dwell doesnt change at all, all temps are solid, and it always cut at 4500 solid not 4501 or 4499, even in neutral or all gears...if you want i could log a file of that even in neutral wich takes a bout 4 seconds to do, but there is no info of the fuel mix because the lc1 isnt connected to ms